


just a training exercise

by beenomorph



Series: numbers [1]
Category: Borderlands (Video Games)
Genre: Choking, Non-Human Genitalia, Other, Rough Sex, Semi-Public Sex, Trans Character, bro i dont know how to use tags, its the classic trope of getting horny while sparring
Language: English
Status: Completed
Published: 2019-09-28
Updated: 2019-09-28
Packaged: 2020-10-28 18:28:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,019
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20783120
Author URL: https://archiveofourown.org/users/beenomorph/pseuds/beenomorph
Summary: “Take it from me, Zer0- kids don’t take too kindly to their parents hooking up with hot strangers,” Moxxi said, then paused. “Or. Uh. Pack members don’t take too kindly to their… Alpha? Hooking up with hot assassins. The metaphor got away from me, hon.”





	just a training exercise

**Author's Note:**

> i've been threatening to write this since before fl4k's character trailer came out and now im actually doing it. ive never written porn before but here u go

Most of the inhabitants of the Sanctuary 3 were asleep. 

It was late- or, it would be late were they still on Pandora. And, considering that most of the denizens of Sanctuary were Pandoran in nature, they almost always slept with the Pandoran sun- despite the fact that Pandoran days stretched unwieldy hours, it was simply human nature to adapt to some sort of circadian rhythm. In spite of the lateness of the hour, there were always nighttime denizens wandering about, of course- Tannis, pouring tirelessly over Eridian text in her laboratory; Small handfuls of Promethean and Edenian citizens mulling about on a different circadian clock than the rest of the crew; Moxxi, chatting idly with whoever was still hanging about the bar at this hour as she closed up; and Zer0, using the quiet as an opportunity to wander about the ship unhindered. 

This was Zer0’s favorite time of the night- or, of the approximated night, since day and night were distinctions of time that only mattered when you were planetside- because it gave him the chance to explore the ship’s halls without attracting much attention. And, admittedly, while he did enjoy clamoring about through service paths and catwalks and vent shafts, that didn’t mean it wasn’t nice to walk around the hallways like a normal person every once in a while.

“Hey, sugar,” Moxxi’s voice drew him from his thoughts, and he glanced in her direction just in time to catch her closing up the bar, the last of the late-night patrons filing out. “My, my, you’re up late. Very gentlemanly of you to wait ‘till I closed up, hon, but I’m too tired for any..._after hours events_, tonight.” She winked, and it only took a second for Zer0 to realize she was teasing.

“I’m out of luck, then,” he responds, flashing her a quick **_;)_**, “I suppose I will settle for walking you home.” ‘Home,’ of course, being her cabin in the crew quarters, but that wouldn’t have fit into the syllable requirement of the haiku, and she got the point anyways.

“Such a charmer!” she responded, grin dimpling her cheeks as she wrapped her arm lazily around Zer0’s. They walked together back towards the crew quarters at a leisurely pace, Moxxi filling the silence with stories about her day with Zer0 as her attentive audience. This was common between them- they were old comrades and unlikely friends, and found comfort in the time together they could snag in their downtimes. There was a war going on, after all, and quiet moments between friends were few and far between.

“...And I never thought I’d see poor Fl4k embarrassed,” Moxxi said, continuing a story she’d started after they’d left the bar, “But I think returning that bottle of bladeflower wine their little jabber stole was the most off-guard I’ve ever seen them, poor thing. Didn’t help that it was mostly empty, and the jabber was passed out over their shoulder.” 

“Meat-thief stole kunai from my room the other day.” Zer0 mused, “It doesn’t like me.”

There was a while, a few weeks back, where Fl4k attempted to convince Zer0 otherwise- their skag and rakks got along with the assassin just fine, and the spiderant was equally indifferent to everyone that wasn’t her master- it was only the jabber that proved anomalous, finding ways to either misbehave or torment Zer0 whenever he was around. It proved fruitless, and Fl4k finally admitted defeat at getting the two to get along when Meat-thief started taking craps in Zer0’s room in retaliation.

“I think it’s the _competition_ the little fella doesn’t like, sugar,” she said, amused tilt to her voice as she smirked up at Zer0, “Since you’re gettin’ so _friendly_ with Fl4k, and all.” Of course. The teasing. It was to be expected, after all- it wasn’t long ago that Zer0 had confided in her his attraction to the beastmaster- it was on a night not unlike this one, where Moxxi was trying to suss out whether or not Zer0 had ever hooked up with Rhys or Lorelei, and his admission of attraction to Fl4k came just as much a surprise to Zer0 as it did to Moxxi. 

But seriously. What was there _not_ to like? They were tall and capable, poetic when they wanted to be, mysteriously cryptic, and so, _so_ good at killing things. That was just about all it took to pique Zer0’s interest. 

“Moxxi,” Zer0 started, an exasperated **_:-/_** flashing over his mask before he was interrupted by her tutting.

“Take it from me, Zer0- kids don’t take too kindly to their parents hooking up with hot strangers,” she said, then paused. “Or. Uh. Pack members don’t take too kindly to their… Alpha? Hooking up with hot assassins. The metaphor got away from me, hon.”

“Moxxi,” Zer0 tried again, expression changing to a projected **_>///<_**. “Stop. I didn’t tell you my thoughts so you could tease me.”

“No,” she hummed, grin turning mischievous as she turned on her heel at the door to her cabin, “You told me so I’d _stop_ teasin’ you. But I’ll stop as soon as you stop making it so fun.” Her expression turns contemplative, “I would have never thought our newest vault hunter was your type- then again, it wasn’t until you told me that I thought you _had_ a type at all… You never did tell me the deal with you and those Atlas folks, after all.” 

“You make me regret asking you for advice, Mox.” Zer0 groaned, exasperated, before clarifying. “_I _am not _their_ type.”

Granted, the only person he knew for sure Fl4k had ever been attracted to was Ellie, and he couldn’t be any more different than their resident mechanic- not to mention that talking about who was or wasn’t interested in Ellie was always an awkward conversation to have with Moxxi in the first place.

“I don’t know, sugar,” Moxxi said, leaning against the door frame of her cabin, resting a hand on her hip. “I wouldn’t be so sure, if I was you. Last I heard, they were doing some training down in the cargo bay. You oughta go down and say hello.” She winked again before turning, door sliding shut behind her, leaving Zer0 alone in the dimly lit commons of the crew quarters.

So, that’s how Zer0 found himself leaning against the railing of the stairs that led down into the open space of the cargo bay, watching Fl4k watch their pets. Even so far removed from its normal context, Zer0 could recognize a training exercise when he saw it- Fl4k was working with their spiderant and skag, Mr. Chew and Broodless, and when they snapped their fingers, the two would lunge at one another. 

The fighting wasn’t really fighting; the attacks were de-fanged, focusing more on technique than on actually harming the other. Zer0 didn’t think, until this moment, that a skag and a spiderant could spar, but it seemed that these two were keen on proving him wrong. With another snap, Fl4k would periodically pause the fighting- once or twice correcting Mr. Chew, who mistook the sparring for play more often than not, or stopping Broodless to prevent her from actually hurting the skag with her over-zealousness, or to reward either of them with treats should their attacks warrant it. 

It was when they were taking a break, after filling the bowl usually clipped to their backpack with water and pushing it towards the two beasts, that they noticed Zer0, raising an arm in greeting. Zer0 noticed then that they were under-dressed-- or, well, a lot of the cobbled-together armor pieces they typically wore were discarded, piled neatly next to where their backpack was resting against the far wall of the cargo bay. 

“Hello, my friend,” Fl4k called up to him, and Zer0 took it as an invitation to descend the stairs and join them on the cargo bay floor. “You’ve been watching for a while, now. Are you enjoying the show?” 

Zer0 shrugged as he joined the other, clasping his hands together in front of him. “I’m enjoying it,” he says, amused, flashing a quick **_:)_** over his visor. “I like watching you work. And... No one else is up.” 

“A good enough reason,” Fl4k replied, squinting down at Zer0 in a way Zer0 had learned, after a while of careful observation, was meant to be friendly. After a moment, they turned back towards their pets, who were now chasing each other in circles, “I don’t think we’re going to get much more done. They don’t want to fight tonight; they want to play.” 

“Training is like both; gaining skill, _and_ having fun.” He paused, … flashing momentarily over his mask before he continued, “Where is the jabber?” 

“Do not worry,” Fl4k responded, this time with a chuckle, “Meat-thief is asleep.”

“I wasn’t worried,” Zer0 huffed, head tilted, arms crossed in mock indignation. “Just... vigilant. I didn’t want to step in shit.” 

“I apologize," Fl4k shuffled awkwardly, idly toying with the hem of their coat, “I know just how difficult jabber shit is to clean.” 

“Don’t apologize. He is the one who crapped in my spare mask, not you.” He punctuated this with another **_:)_**, and Fl4k squint-smiled once more, a companionable silence settling over them.

"You speak in haiku," Fl4k hummed, breaking said companionable silence as they crossed their arms over their chest, watching as their pets romped around, the point of the training long since lost. "I thought you sought a challenge. Does that really count?"

Zer0 snorted, an amused **_:->_** flashing for a moment over his mask. "That's easy for you to say. I do it because--" he paused, then, head tilting inquisitively. He’d recognize the cadence of a haiku just about anywhere by this point, but ran over Fl4k’s phrasing once more in his head to be sure. "Was that on purpose?"

"Was what on purpose?" Fl4k parroted, the monotone of their voice hiding their own amusement, "I didn't say anything off-putting, did I?" 

“Definitely purposeful. Are you mocking me, or challenging me?” Of its own accord, Zer0’s voice had taken something of a playful air, a quick **_?_** flashing across his visor.

“Neither. If it were a challenge I wanted, I would ask you to spar.” They paused before continuing, dropping the meter, “Haiku isn’t a challenge, really.”

“But sparring would be?” Zer0 hums, “Since your pack has lost focus, we could spar instead. Rather than fight with words, we fight with our bodies.” He paused, tilting his head towards Fl4k. “If you’re up for it.” A **_;)_** flashed over his visor, despite his thinking that this was very much a bad idea on his part. 

Way back when, after Zer0 first joined the Sanctuary crew proper, and not long after he’d accidentally revealed to Moxxi the whole _‘holy crap that new vault hunter is hot as hell’_ thing, she’d urged him on several occasions to try out _flirting_ with them, what with _saying nice things and initiating physical contact_. Zer0 wondered if this exchange had counted for either, and then felt embarrassed for thinking it in the first place, as silence drifted between them for a moment while Fl4k considered his offer.

Zer0 didn’t like this silence, as compared to the one before- he wasn’t used to feeling so on the spot, god forbid he ever feel _embarrassed_ around someone- but after another moment Fl4k shrugged.

“I accept your offer. I hope you aren't distracted by counting syllables,” They turned, then, snapping to get their pets attention before sending the pair off. 

“Wouldn’t dream of it,” Zer0 responded, undoing the straps on the digi-sheath for his sword, “I am not so easily distracted, you know.” He deposited it carefully alongside Fl4k’s belongings, rolling his shoulders. They took their places in the open space of the cargo hold, and Fl4k waited patiently as Zer0 did a quick stretch. He felt a momentary pang of jealousy- Fl4k had no muscles to cramp, after all, which must streamline their training process beyond measure. 

“Are you ready?” Fl4k said as Zer0 stood up straight, and he nodded in response. He bowed politely, a gesture returned by Fl4k after only a moment’s hesitation, before he adopted a loose, informal stance. And then, the actual fighting started.

Zer0 was faster than Fl4k, an advantage he played to when they darted forward, throwing a loose punch. Zer0 could tell it wasn’t really made with the intention to connect, moreso with curiosity behind it- a desire to see Zer0’s reaction more than anything. Zer0 ducked under their arm, sliding forward with his momentum until he stood behind Fl4k.

It was simple, then, to grab the collar of their oversized coat and tug, taking advantage of the balance shift following their punch, sending them stumbling backwards a few steps. Fl4k had to realize how inconvenient such a garment could be during battle, giving one’s opponent more things to grab and making oneself a wholly bigger target. Right?

Their jacket was wrenched from Zer0’s grip as they whirled around, using the momentum of their stumble to speed up the action. Zer0 didn’t let up, though, following their movement to once more take position behind them, this time sweeping a kick at Fl4k’s legs, yanking their coat with more force. Fl4k grunted as they tipped backwards, knee buckling from Zer0’s kick, the tug on their jacket giving them no chance to regain their balance before they fell, back hitting the cold ground of the cargo bay floor as Zer0 leaned over them.

“This is a hindrance,” he said, squatting beside Fl4k to tug much more gently at their lapels, mask flashing an amused **_:->_**. “You should have taken it off. How do you--” It was at that moment that he was interrupted as Fl4k looped an arm around his knee, rolling upwards and pulling quicker than Zer0 had anticipated. And so, they switched places- Zer0, prone on his back with Fl4k squatting at his side, Fl4k holding Zer0’s leg hostage, resting at an uncomfortable angle against their shoulder, and Zer0 thinking that yes, oh yes, this had been a very poor decision on his part. 

“And that,” Fl4k said, voice smug, “Was a distraction.” 

It took Zer0 a moment to focus on the words coming out of his mouth instead of the way Fl4k threw his leg casually over their shoulder, or the weight of their body against his thighs, keeping him in place. 

“So, playing possum?” He said, finally, once the shock had worn off, “Learned helplessness isn’t a great battle technique.”

“Oh?” Fl4k said, leaning forward in a way that twisted Zer0’s leg in a way that was uncomfortable, just shy of pain, but an obvious demonstration of Fl4k’s control- if they _wanted_ to hurt Zer0, they could have, and something about that made Zer0’s stomach clench. “It seems to have gotten you where I want you.” 

Zer0 figured, in that moment, he had one of two options- sit there and let his brain melt from being flustered, or pretend he wasn’t, and keep up the guise that he wasn’t at all aroused by literally everything that had just happened.

“Don’t be so sure, Fl4k. That would make us one for one, right? Let’s continue.” 

And so, they did. It helped to clear his head a bit, falling into the rhythm of sparring. Even still, it was a hard thing- he’d slipped up more than he would have liked, and knew Fl4k could likely tell he was distracted. He doubted, however, that Fl4k would guess the source of his distraction- it was late, Zer0 could argue that he was just more tired than he’d originally thought, not that he was horny. It felt crass to think it so plainly, but that’s what it was- Fl4k was grace and strength and power; Zer0 thought it enough of a marvel to see them in action, but sparring with them revealed that even more so. Were he not undeniably attracted to the beastmaster, he’d likely be better able to appreciate these traits- instead, his stomach tied itself up in knots at every touch they shared, face flushing beneath his mask at every word Fl4k spoke during their combat. 

“You are distracted,” Fl4k said, and didn’t wait for a response before tackling him outright- it was a move that would never have worked on Zer0 had he been focused, which made him feel embarrassed by being caught so obviously off guard. Zer0 rolled, or tried to, uncharacteristically clumsy in his motions. Fl4k stopped him in his tracks, though, using one hand to pin his arms above his head, pushing their knee into his chest to send him back to ground with a thump. 

And whatever facade Zer0 hoped to construct about being off-kilter because he was tired dissolved at his body’s response- he gasped, choking out a soft moan, arching slightly underneath Fl4k’s knee; then froze, completely rigid underneath them as he realized what he just did.

"Oh," Fl4k said, surprise evident in their voice, "So you _are_ aroused." 

The involuntary**_ ///_** that flashed over his visor did little to actually convey his mental state- he was flushed beneath his mask, still breathless from sparring, and dealing with the reality of being pinned to the ground by a person he found very attractive, and he felt more frazzled than he had in… Ever, probably. 

He wiggled slightly underneath the pressure of Fl4k's knee on his chest- they hadn't moved, despite their revelation, and Zer0 felt his brain scrambling for a response.

"I am…" He paused, not liking the needy wobble his voice had taken. Steeling himself, he took a breath before he continued. “So sorry. This is terribly awkward. This… never happens?" he offered halfheartedly. He sighed, a shaky sound, then cleared his throat. “You don’t sound surprised. Was my infatuation truly unsubtle?” 

“I had a suspicion,” Fl4k said, and Zer0 was very aware of the way their gaze drifted for a moment, dragging across Zer0’s form before snapping back up to his visor. “But I wanted to be sure, first.”

“First? What do you-” his thoughts and words were cut off with another gasp, then, this one muffled as he bit his lip beneath his mask in response to Fl4k shifting their knee from his chest to instead slot it between his thighs, using the hand that wasn’t currently pinning Zer0’s to hook under his chin. They tilted his mask up, spending a moment scrutinizing them before continuing.

“I think,” they said, voice dropping impossibly lower, free hand leaving Zer0’s mask to trail down their chest, deceptively gentle, narrow fingers resting at Zer0’s belt. “It is my turn to make an offer.”

“And that offer is?” Zer0 countered, regaining some of his composure while using every ounce of restraint he had not to roll his hips up against Fl4k’s hand, or the knee between his thighs. “How can I accept if I don’t know what you want?” 

“I want,” Fl4k drawled, hooking fingers around Zer0’s belt, tugging him up at an angle against their knee, “To fuck you until you can no longer stand.” They paused, squint-smiling once more, now smug. “If you’re up for it.” They mirrored Zer0’s earlier statement teasingly, and Zer0 held his breath a moment, **_!!! _**appearing on his visor.

“You want to right now? Here, on the cargo bay floor? How _conspicuous_.” 

“Not if you can keep quiet.” Fl4k countered, leaning forward in an almost conspiratorial way. They punctuated the statement by tugging Zer0’s belt once more, grinding their knee against the meet of his thighs in a way that made his breath stutter as he only halfway suppressed his moan. “Hm. That could be more difficult for you than I thought.” 

“I can stay quiet,” Zer0 insisted, skeptical tune changing quickly as his brain lost the battle with his arousal, and he rolled his hips against Fl4k’s leg in a way he knew was needy but was far past caring about. “I can—_ah_,” he was cut off again by his own response to Fl4k’s idle exploration of his body with their free hand- his belt was abandoned, now, in favor of cupping Zer0’s crotch entirely, the light pressure of their fingertips sending pure want stabbing into Zer0’s gut at each motion. 

“You can…?” Fl4k teased, and Zer0’s mask flashed **_>:( _**in a silent response. 

“You,” Zer0 responded, “Can take them off, if you won’t give my hands back. At least get the belt.” 

“Needy.” Fl4k observed, but went to work anyways- it was a difficult maneuver with the way Zer0’s suit was constructed, but they managed with only minimal confusion. When Fl4k slid their hand passed Zer0’s waistband, fingers touching the surprisingly smooth skin of Zer0’s stomach, he hissed through clenched teeth, twitching. 

“Cold hands,” he clarified before Fl4k could pull away, his voice a strained whisper, “Keep going.”

Fl4k’s confidence faltered for the first time that night when their fingers actually reached Zer0’s slit, slick and swollen from where he’d been grinding against Fl4k’s leg. They stroked gently along its length, mapping out the unfamiliar territory as Zer0 shook beneath them, breath coming in shallow gasps. It was when Fl4k added more pressure, rubbing firm circles into the oversensitive skin that Zer0 gasped, sharply, head lolling back, helmet hitting the floor with a dull clunk. Fl4k could feel Zer0 shift, slit opening beneath their fingers, the wet sound of his member pushing its way free muffled by his pants. 

“Oh,” Fl4k said, quietly, more to themself than to Zer0, who let out a breath he didn’t realize he was holding.

“I should have warned you,” he started, “That I'm not entirely human, in most ways...” Fl4k shrugged with one shoulder.

"And neither am I." They responded, "I am curious, though. You said I could take these off?" Zer0 restrained himself from whining as Fl4k pulled their hand away, instead resting once more on his waistband. "I want to see what you look like." Zer0 shivered, but didn't respond right away, instead craning his neck up to look around the room- he knew there weren't witnesses, but still, it never hurt to be safe.

"Yes. Quickly," he breathed, and Fl4k complied, tugging Zer0's pants down past the subtle curve of his hips. To Zer0's relief, they kept their commentary brief.

"Beautiful," they said, voice a deep rumble that made Zer0's entire body flush, mask flashing with a quick **_>///<_**. The skin of Zer0's thighs was unnaturally pigmented, almost black, patterned with directionless whorls of pale discoloration, crisscrossed with scars from god knows what that Fl4k traced gently, almost reverently. 

"Flatterer." he snorted in response, thinking that's the last word he'd use to describe his own junk. It was mostly internal, sensitive skin hidden behind its protective sheath, slick enough to leave a dark spot on the fabric of his pants. 

It was from there that his cock sprang free-- well, not a cock in the traditional sense, but a close enough analog in Zer0's opinion. About the length of his palm, it was comprised of three smaller appendages that surrounded his entrance, twining together with his arousal, writhing desperately against Fl4k's hand and leaving stripes of his own slick in its wake. 

Fl4k wasted no time familiarizing themselves with Zer0, their first cursory strokes making way for a much faster rhythm, spurred on by the increasingly desperate responding thrusts of Zer0’s hips. He lolled his head back once more, biting his lip to keep back the keen that threatened to escape him as his cock unfurled, appendages curling around Fl4k’s fingers instead of each other. Fl4k took this in stride, the slick noise of their stroking filling the air between them.

He failed to hold the sound he made when Fl4k gave a sharp tug, a twist of their wrist. It was a lot- Zer0 was tightly wound up, fingers digging hard into his own palms as he writhed beneath Fl4k, the harsh treatment of his sensitive skin momentarily overwhelming. It _hurt, _is the thing, but it was a good kind of hurt, the kind where pleasure and pain coiled together in his gut and filled his brain with a pleased fog. His mouth stuttered uselessly over the shapes of half-finished words of encouragement, a hoarse babbling whisper as some part of his brain tried desperately to keep quiet. 

“You like that?” Fl4k hummed.

“_Yes,_” Zer0 barely managed to respond, mask flashing **_<3, _**before Fl4k repeated the motion- this time harder, faster, and Zer0 gasped, back arching, his climax coming as a surprise to them both. Fl4k’s hands slowed as he shuddered beneath them, though they continued rubbing firm circles at the base of his members with their thumb, fingers threaded between them. Zer0’s helmet flashed a few more times before he stilled, thighs still trembling from his climax, aware and uncaring of Fl4k’s gaze directed downwards to where his entrance clenched around nothing.

They leaned back, then, relinquishing their hold on Zer0’s wrists to drag newly-freed fingers through Zer0’s wetness, watching with a contained interest as come mixed with the sweat rolling down Zer0’s thighs, dripping onto the fabric of Fl4k’s pants and the cargo bay floor. Zer0 propped himself up on his elbows just in time for Fl4k to push two of their fingers in with little pretense, sending a shiver rolling through his body. Zer0 reached out, then, sitting up fully as his body moved of its own volition, hands clenching around the front of their coat. Their fingers were thicker than Zer0’s own, and the feeling of the grooves from their mechanical joints was unfamiliar, but not unwelcome.

Zer0 tugged on Fl4k’s coat while they fingered him open, pulling the ragged fabric over their shoulders just enough to get a look at Fl4k’s form beneath their coat- shaky hands traced the hard, mechanical lines of their frame, hands instinctively closing around rib-like protrusions as they curled their fingers inside of him. He took a moment to regain his composure before continuing his exploration downwards, hands resting on Fl4k’s belt.

“Not yet,” Fl4k said, simply, curling their fingers inside him once more, pairing the motion with a stroke of Zer0’s cock. Zer0 groaned, grinding his hips up into Fl4k’s hands before responding.

“Why not? Can I not touch you, too? I don’t want to have all of the – _fuck,” _Zer0 cut himself off as Fl4k pushed their third finger in with a snap of their wrist, “_Fun_. All of the fun.” He corrected himself, though halfheartedly, chest heaving.

“You are not yet ready,” They said, smugness at having compromised Zer0’s meter rolling off them in waves.

“I am _quite _ready,” Zer0 protested, snapping his hips up to meet the pace of Fl4k’s thrusting, “For your offer to be fulfilled. I could still walk.”

“Patience is a virtue,” Fl4k responded, spreading their fingers in a way that made Zer0 stutter around his retort.

“Chastity is too. Virtuosity isn’t either of our strengths.” Zer0’s mask flashed **_;) _**for just a moment, switching quickly to **_! _**as Fl4k withdrew their fingers as suddenly as they’d entered, using their newly freed hand to push hard on Zer0’s chest. He didn’t resist- in part because it caught him by surprise, and in part because he didn’t _want _to- when Fl4k pushed him back down onto the cargo bay floor, untwining their other hand from Zer0’s cock to yank his pants past his knees to make it easier for Fl4k to get between them.

Zer0 took well to the change of position, shifting in such a way to cross his ankles behind Fl4k, pressing his thighs in to draw the other closer. Fl4k remained propped on their knees, loosening their belt enough to tug their pants over the skeletal curve of their hips. Fl4k huffed a quiet groan, a small puff of steam curling from their frame as it fought to keep cool, and Zer0 heard the hiss of some sort of mechanical release as their own cock slid free into their hands. It was, in all honesty, bigger than Zer0 had been expecting- and he watched with hungry eyes as Fl4k gave themselves a few steady strokes. The sight of his come slicking Fl4k’s cock sent a whole-body pulse of want cascading through him, and he shook from underneath the hand still steady on his chest.

“Oh _my_, beastmaster,” Zer0 said, voice an appreciative hum as his eyes dragged across Fl4k’s length, “What purpose does this mod have in your line of work?”

They lowered their hips to Zer0’s, dragging their length slowly across his slit. The twitching of their cock against him gave away their arousal moreso than their ever-calm voice as they responded, “Would you like me to show you?”

“Do you need to ask?” Zer0 said, sarcastic and breathless, “I thought we had established—”

Zer0 was starting to think Fl4k just _liked_ catching him off guard, and his words gave way to a shaky moan as Fl4k pushed their cock inside with a shallow thrust. They moved their hand up, then, metal fingers leaving Zer0’s chest in favor of curling around his throat, pressing hard enough to make him gasp but not to cut off his air supply entirely.

“Be quiet.” Fl4k warned, then loosened their grip just so, thumb tracing over the fabric covering Zer0’s windpipe. He wondered if Fl4k could feel his pulse through the suit, if they were aware of the way his heart hammered away in his chest.

“Make me,” Zer0 challenged, and Fl4k squinted down at him, tilting their head. They squeezed then, far tighter, leaving Zer0 gasping beneath them for a moment before slamming their hips forwards, fast and hard. Would that he could, Zer0 would have cried out at that—he instead settled for a few shallow gasps as he rolled his hips up, wishing Fl4k was impossibly closer. They didn’t relent, however, their free hand clamping on Zer0’s hip to keep him still.

“_Fl4k_,” Zer0 breathed, hands once more balling around handfuls of their coat. Fl4k loosened their hold on his throat, and Zer0 gasped a few hungry breaths. Even without the oxygen denial, the pairing of pleasure and pain that mingled throughout his frame was enough to make him lightheaded- he wasn’t wet enough to take Fl4k, really, but he didn’t care; they were only halfway in and the stretch was fucking phenomenal. He reached a hand down between his legs, curling his own fingers around his members, groaning as Fl4k rewarded that action with another squeeze to the throat, another shallow thrust of their hips. Zer0 hissed at that through clenched teeth, body tensing around them, and they paused.

“Keep going,” he whined, tugging on Fl4k’s coat with the hand still tangled there, “Please, Fl4k, I need you to keep going, before I go –” he groaned, frustrated at himself for breaking meter, “Before I go crazy. Damn it, just fuck me already—”

Fl4k definitely had a comeback for that—he didn’t need to be able to comprehend them to know when they were being smug—but Zer0 was far too lost in the sensation of their rolling hips, the steady thrust of their cock as they pushed impossibly deeper. Their pace was merciless, delayed only once, long enough for them to prop themselves up on their knees once more, tugging Zer0 up along with them.

Beneath them, Zer0 writhed. His hands tugged for a moment at Fl4k’s coat once more as he arched and shook, clawing momentarily over his own face as if he could muffle himself through his mask. Fl4k responded in kind, hand tightening around Zer0’s throat once more, forcing him to gasp and stutter. In the silence of the cargo bay, the wet sound of Fl4k fucking him felt obscenely loud, paired with the rhythmic thump of their bodies against the cold floor, with the sound of Fl4k’s plating slapping against Zer0’s thighs, working bruises into the skin.

It’s almost too much, the feeling of working himself with his hand while Fl4k fucked him, his hyperawareness of every groove and ridge and segment of their mechanical cock, the way it pulled and pushed and stretched him with each thrust of their hips. The feeling of Fl4k’s hand around his throat—tight enough to make him gasp, to struggle for air even as his breathing got heavier, paired with the steady building pleasure in his gut, was all sending Zer0 teetering on the edge of complete overstimulation. There’s an excitement, too, an excitement that came with all of this happening in the fucking _cargo bay, _in the middle of the floor, with the pair hardly trying to be inconspicuous that added to the overwhelming feeling of _this. _

“More,” Zer0 gasped, brain entirely monosyllabic, “Harder, Fl4k. _Please_,” he tacked on at the end, and Fl4k snapped their hips down, thrusting hard and fast. Another wisp of steam curled from one of Fl4k’s exhausts, paired with the quiet sound of their internal fans clicking on to help cool their frame. Zer0’s hands left his mask in favor of closing around the arm Fl4k had on their throat and he arched, thighs squeezing around Fl4k’s hips as he came, rolling his own hips up again to meet Fl4k’s.

“There we go,” Fl4k hummed, voice tight with the strain of their own arousal, “That’s a good boy.”

Their own climax followed shortly after- it was far less dramatic than Zer0’s- a sharp snap of their hips down, their internal fans ticking up slightly higher, the light of their eye dimming as power surged through their frame. Zer0 gasped at the feeling of Fl4k’s release, shivering as they pulled out, a mixture of both of their fluids pooling out of Zer0 in the wake of their cock.

Despite it, though, Zer0 was glad when Fl4k shifted to the other side of his legs, pulling up his pants and refastening his belt. He grimaced beneath his mask at the feeling- but he could shower later, and didn’t want to have his pants down in the cargo bay longer than he absolutely needed. They took only a moment to compose themselves- their cock slid back into its sheath, pants tugged back up over their hips—before they stood, leaned down, and picked up Zer0 from where he laid useless on the floor.

“It’s not like I expected you to walk back to your quarters,” they said in response to the **_! _**that flashed over Zer0’s mask, humored by his shock, “That was part of my offer, after all.”

“I need to clean up,” Zer0 said, voice hoarse and deep as he looked over Fl4k’s shoulder to the splatters they’d left on the floor, “We cannot just _leave _that there. Frankly, it’s obscene.”

“I’ll worry about that.” Fl4k said, simply, and Zer0 didn’t protest as they carried him the short distance from the cargo bay to his quarters. “Let us worry now about getting you cleaned up.”

“Good idea,” Zer0 said, mind wandering back to that shower he thought about earlier. He wondered if Fl4k would like to join him. Some other time, maybe.

Fl4k set him down gently in his room, on the seldom-used cot kicked into the corner. Fl4k worked quickly with Zer0’s instruction- peeling off Zer0’s sex-stained pants with a confidence that came from the privacy of the space, helping him clean off when his exhaustion-heavy limbs weren’t doing the trick. Zer0 kept his spare clothes underneath his cot, and was able to retrieve replacements quite easily.

“I enjoyed this,” Fl4k hummed, squint-smiling as they sat on the edge of his cot after he’d re-dressed himself, and Zer0 responded with a **_;)_**.

“I want a rematch. I’m much better at sparring when I’m not…”

“Horny?” Fl4k offered, and Zer0 sputtered, the surprised laugh curling from his chest genuine.

“I was going to say ‘_aroused_.’”

“It works either way.” Fl4k responded. They stood, then, hovering awkwardly beside Zer0’s cot before giving the assassin a quick squeeze on the shoulder.

“Rest,” they said, softly, “And I will see you when you rise.”

And like that, they were gone, leaving Zer0 alone in the darkness of his room, near sleep, thinking about how he _really_ owed Moxxi one for the advice. 

**Author's Note:**

> ftr its not mentioned in this fic (bcz i cut the dialog about it since it didnt fit The Mood) but zer0 is a nonbinary trans man, uses he/him but his gender is like none pizza left beef.none gender left masc. no im not projecting. check out my nsfw [twitter acct](https://twitter.com/deletelater__) to see all my fl4k/zer0 rambling


End file.
